
236 Microwave Engineering
7.8a) or choke joint (or choke ange) (Figure 7.8b). Both of these are made of
brass, precisely machined and tted to the outer dimensions of waveguides.
Cover anges are simple, cheap and thus most commonly used in labora-
tories. Choke anges, however, reduce the leakage of energy resulting in
improved VSWR of the system and thus are used in actual setups.
The choke joints provide good electromagnetic continuity between sec-
tions of waveguide with very little power loss. A cross-sectional view of a
choke joint is shown in Figure 7.8b. A pressure gasket is to be provided between
the two metal surfaces to